1. School of Earth Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia
2. CSIRO Land and Water, Private Bag No. 5, Wembley, Western Australia 6913, Australia
3. National Centre for Groundwater Research and Training, Adelaide, South Australia 5001, Australia
4. School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia 6009, Australia
5. Department of Chemistry, Barnard College, 3009 Broadway, New York, New York 10027, United States
6. Lamont-Doherty Earth Observatory, PO Box 1000, 61 Route 9W, Palisades, New York 10964, United States